Ultra-thin thickness electromagnetic-wave absorption property and excellent corrosion resistance in weak-magnetic FeCr0.5NiCu0.5 high-entropy alloy

High entropy alloys (HEAs), due to their designable crystal structure, variable electromagnetic properties, and excellent corrosion resistance, have been widely investigated as electromagnetic wave absorbing materials in last decade. In this work, FeCr0.5NiCu0.5 flaky powder, exhibiting ultra-thin thickness electromagnetic-wave absorption property and excellent corrosion resistance, has been produced by gas atomization and ball milling techniques. The FeCr0.5NiCu0.5 coarse and fine flaky powders show the minimum reflection loss of -26.1 dB and -16.9 dB both at 14.1 GHz, respectively. The thickness corresponding to the maximum effective absorption bandwidth (EAB) of the coarse powder (3.6 GHz) and fine powder (2.5 GHz) are 1.2 mm and 0.7 mm, respectively, which are only similar to 1/2 and similar to 1/3 of the thickness corresponding to the maximum EAB in traditional HEA absorbing materials. In addition, both the FeCr0.5NiCu0.5 coarse and fine flaky powders exhibit significantly better corrosion resistance than carbonyl iron powder (CIP) under the same condition, with the corrosion current density two orders of magnitude lower than that of the CIP. Efficient preparation process on a large scale, good wave absorption properties, ultra-thin thickness, and excellent corrosion resistance, endow the FeCr0.5NiCu0.5 HEA great potential for high performance electromagnetic wave absorption materials in harsh-environment.